GPT4oさんが作ってくれた文面><;
Did you know? The Federal Highway Administration (FHWA) has found that for rural two-lane highways, 11-foot lanes are just as safe as 12-foot lanes in terms of crash performance. While 12-foot lanes are often used on higher-speed roads like interstates, the data shows that narrower lanes can work perfectly well—and even provide benefits in specific contexts like cost savings and space for other uses.
For more details, here's a reference:
https://safety.fhwa.dot.gov/geometric/pubs/mitigationstrategies/chapter3/3_lanewidth.cfm